[klondike98]

Those wine colored push buttons can be warmed a little with a hair dryer.  Ed at Renovated Radios has the following on his site: "NOTE: It helps to warm the end of the buttons with a hair dryer prior to installing them. Not too warm though or they will bend. Just soften them up enough to allow them to slip on easily."

I expect that the reverse would be true as well.  A little warming and you could narrow them a bit for a tighter fit.  You could also put a piece of paper over the metal and slide the button over that to give a little tighter fit. I'd avoid gluing it in case you wanted to take them back off.